Alkali Metals
The Alkali metals are in group one, and periods two through seven.
The elements in this group are as followed:
-Lithium
-Sodium
-Potassium
-Rubidium
-Cesium
-Francium
These elements are all solids.
Sodium
Physical Properties
Physical properties that we found out about these are that they are all soft, with low melting and boiling temperatures. They have low densities, and they show relatively weak metallic bonding as only one electron is available from each atom. Alkali metals have colored flames such as:
Lithium- red
Sodium- yellow
Potassium- lilac
Rubidium- red
Cesium- blue
Other physical properties of the single elements are as followed:
Lithium has been used in H-bombs and manic-depressives, sodium is too violent for everyday uses, potassium may be the cause of genetic mutations, rubidium is slightly radioactive. It is used to locate brain tumors. Cesium is the softest metal, and francium has never been seen by the human eye, we only have the formula for this element.
Chemical Properties
They can reduce oxygen, chlorine, ammonia and hydrogen,and the reaction with oxygen tarnishes the metals in air, so they are stored under oil.
The alkali metals form ionic solid oxides of composition M2O when burnt in air. However, Na also forms the peroxide Na2O2 as the main product, and K forms the superoxide KO2, also as the main product. Since the alkali metals are the most electropositive (the least electronegative) of elements, they react with a great variety of nonmetals. In its chemical reactivity, lithium more closely resembles Group 2 because it is less reactive with water, oxygen, and halogens then the rest if the metals in its own group.
~Interesting Facts~
Its reaction to water
The alkali metal group reacts easily with atmospheric oxygen and water vapor. They react forcefully, and often violently, with water to release hydrogen and form strong caustic solutions.
Alkali metal salts were known to the ancients. The old testament refers to a salt called neter (sodium carbonate), which was extracted from the ash of vegetable matter. Saltpetre (potassium nitrate) was used in gunpowder, which was invented in China about the 9th century A.D. and had been introduced into Europe by the 13th century.
In the 19th century the only use for the alkali metals was the employment of sodium as a reagent in the manufacture of aluminum.
Sodium and potassium are the sixth and seventh most abundant of the elements, constituting, respectively, 2.6 and 2.4 percent of earth's crust isotope. The other alkali metals are considerably more rare, with rubidium, lithium, and cesium, respectively, forming 0.03, 0.007, and 0.0007 percent of earth’s crust. Francium, a natural radioactive i, is very rare and was not discovered until 1939.
Where Alkali metals are located-
Common Uses for Alkali Metals
Sodium is by far the most important alkali metal in terms of industrial use. Hundreds of thousands of tons of commercial compounds that contain sodium are used annually, including the common salt (NaCl), baking soda (NaHCO3), sodium carbonate (Na2CO3), and caustic soda (NaOH). Potassium has less use than sodium as a free metal. Potassium salts are consumed in tonnages in the manufacture of fertilizers. An important use of lithium is in the use of lightweight batteries. Primary lithium batteries (not rechargeable) are widely used in many things such as cameras, cellular telephones, and pacemakers. Rechargeable lithium storage batteries that could be suitable for vehicle propulsion or energy storage are the subject of intensive research. Rubidium and cesium and their compounds have limited use, but cesium metal vapor is used in atomic clocks, which are so accurate that they are used as time standards.
Group One of The Periodic Table. Digital image. Bitesize. BBC. Web. 25 Oct. 2009. <http://images.google.com/imgres?imgurl=http:www.bbc.co.uk/schools/gcsebitesize/science/images/periodictable_group1.jpg&imgrefurl=http://www.bbc.co.uk/schools/gcsebitesize/science/add_ocr/periodic_table/group1rev1.shtml&usg=__rsOkWpaphBZr-XN2gAR8MXpFQDU=&h=307&w=546&sz=30&hl=en&start=26&sig2=2H_xRNgILTABIfyMFdRTIg&um=1&tbnid=UfVTOr9hXN7gcM:&tbnh=75&tbnw=133&prev=/images%3Fq%3Dalkali%2Bmetals%26ndsp%3D20%26hl%3Den%26sa%3DN%26start%3D20%26um%3D1&ei=Iu3kSsOQAZqwNPiF9fQP>.
The Alkali metals are in group one, and periods two through seven.
The elements in this group are as followed:
-Lithium
-Sodium
-Potassium
-Rubidium
-Cesium
-Francium
These elements are all solids.
Physical Properties
Physical properties that we found out about these are that they are all soft, with low melting and boiling temperatures. They have low densities, and they show relatively weak metallic bonding as only one electron is available from each atom. Alkali metals have colored flames such as:
Lithium- red
Sodium- yellow
Potassium- lilac
Rubidium- red
Cesium- blue
Other physical properties of the single elements are as followed:
Lithium has been used in H-bombs and manic-depressives, sodium is too violent for everyday uses, potassium may be the cause of genetic mutations, rubidium is slightly radioactive. It is used to locate brain tumors. Cesium is the softest metal, and francium has never been seen by the human eye, we only have the formula for this element.
Chemical Properties
They can reduce oxygen, chlorine, ammonia and hydrogen,and the reaction with oxygen tarnishes the metals in air, so they are stored under oil.
The alkali metals form ionic solid oxides of composition M2O when burnt in air. However, Na also forms the peroxide Na2O2 as the main product, and K forms the superoxide KO2, also as the main product.
Since the alkali metals are the most electropositive (the least electronegative) of elements, they react with a great variety of nonmetals. In its chemical reactivity, lithium more closely resembles Group 2 because it is less reactive with water, oxygen, and halogens then the rest if the metals in its own group.
~Interesting Facts~
The alkali metal group reacts easily with atmospheric oxygen and water vapor. They react forcefully, and often violently, with water to release hydrogen and form strong caustic solutions.
Alkali metal salts were known to the ancients. The old testamen t refers to a salt called neter (sodium carbonate ), which was extracted from the ash of vegetable matter. Saltpetre (potassium nitrate) was used in gunpowder, which was invented in China about the 9th century A.D. and had been introduced into Europe by the 13th century.
In the 19th century the only use for the alkali metals was the employment of sodium as a reagent in the manufacture of aluminum.
Sodium and potassium are the sixth and seventh most abundant of the elements, constituting, respectively, 2.6 and 2.4 percent of earth's crust isotope. The other alkali metals are considerably more rare, with rubidium, lithium, and cesium , respectively, forming 0.03, 0.007, and 0.0007 percent of earth’s crust. Francium, a natural radioactive i, is very rare and was not discovered until 1939.
Where Alkali metals are located-
Common Uses for Alkali Metals
Sodium is by far the most important alkali metal in terms of industrial use. Hundreds of thousands of tons of commercial compounds that contain sodium are used annually, including the common salt (NaCl), baking soda (NaHCO3), sodium carbonate (Na2CO3), and caustic soda (NaOH). Potassium has less use than sodium as a free metal. Potassium salts are consumed in tonnages in the manufacture of fertilizers. An important use of lithium is in the use of lightweight batteries. Primary lithium batteries (not rechargeable) are widely used in many things such as cameras, cellular telephones, and pacemakers. Rechargeable lithium storage batteries that could be suitable for vehicle propulsion or energy storage are the subject of intensive research. Rubidium and cesium and their compounds have limited use, but cesium metal vapor is used in atomic clocks, which are so accurate that they are used as time standards.
Works Cited
"Alkali metal (chemical element) -- Britannica Online Encyclopedia." Encyclopedia - Britannica Online Encyclopedia. Web. 25 Oct. 2009. <http://www.britannica.com/EBchecked/topic/15617/alkali-metal>.
Group One of The Periodic Table. Digital image. Bitesize. BBC. Web. 25 Oct. 2009. <http://images.google.com/imgres?imgurl=http:www.bbc.co.uk/schools/gcsebitesize/science/images/periodictable_group1.jpg&imgrefurl=http://www.bbc.co.uk/schools/gcsebitesize/science/add_ocr/periodic_table/group1rev1.shtml&usg=__rsOkWpaphBZr-XN2gAR8MXpFQDU=&h=307&w=546&sz=30&hl=en&start=26&sig2=2H_xRNgILTABIfyMFdRTIg&um=1&tbnid=UfVTOr9hXN7gcM:&tbnh=75&tbnw=133&prev=/images%3Fq%3Dalkali%2Bmetals%26ndsp%3D20%26hl%3Den%26sa%3DN%26start%3D20%26um%3D1&ei=Iu3kSsOQAZqwNPiF9fQP>.
"Visual Elements: Group 1 - The Alkali Metals." Royal Society of Chemistry, the largest organisation in Europe for advancing the chemical sciences. Web. 25 Oct. 2009. <http://www.rsc.org/chemsoc/visualelements/Pages/data/intro_groupi_data.html>.
"The history and use of our earth's ... -." Google Books. Web. 26 Oct. 2009. <http://books.google.com/books?id=yb9xTj72vNAC&pg=PA39&lpg=PA39&dq=what+period+and+group+are+alkali+metals+found%3F&source=bl&ots=iuTWt_AD28&sig=H09bSE37zJhEJme2u2EQMxh_hY4&hl=en&ei=KObdSojKK4-4MLvl2fQN&sa=X&oi=book_result&ct=result&resnum=2&ved=0CBAQ6AEwAQ#v=onepage&q=what%20period%20and%20group%20are%20alkali%20metals%20found%3F&f=false>.
Padilla, Michael J., Ioannis Miaoulis, and Martha Cyr. Physical Science. Saddle River, New Jersey: Pearson Education, Inc., 2009. Print.
Urgitis, Justin. Sodium. Digital image. About.com: Chemistrey. 2009. Web. 26 Oct. 2009. <http://chemistry.about.com/od/elementgroups/a/alkalimetals.htm>.
Alkali's reaction with water. Digital image. Junior Cert Science - Chemistry - Periodic Table//. Web. 26 Oct. 2009. <http://www.sciencequiz.net/jcscience/jcchemistry/metals/metals1a.htm>.